As I have pointed out before, the Lachmann radical subjectivists have ideas in common with the Post Keynesians, and there might well be scope there for mutual constructive dialogue – and that is why I have not attacked them. There are certainly ideas in various strands of Austrian economics that Post Keynesians can agree with, such as:

(1) money is not neutral;
(2) capital goods are heterogeneous;
(3) we face fundamental uncertainty in economic life, uncertainty in the sense of Knight and Keynes which is not measureable risk;
(4) expectations are subjective.

For example, one important similarity between the Lachmann radical subjectivists and Post Keynesians is the view that expectations are subjective:

“The natural extension of the subjectivist concept from preferences to expectations implies that Austrian views on human action and market processes and Keynesian theory on the instability of investment are complementary. Within the Keynesian understanding Shackle did much to ensure consistency and clarity in the Keynesian understanding of the role of subjective expectations. Lachmann did the same for Austrian economics. Because both Lachmann and Shackle were open to the views of subjectivists from other schools, the result is a large measure of similarity in (some) Austrian and post-Keynesian theories on the role of expectations. The similarity is such that Lachmann (1978: 15) considered Shackle an Austrian even though Shackle considered himself a Keynesian” (Burger 2003: 104-105).

Indeed, the Austrian school is itself split between the Lachmann-wing and the moderate subjectivists who have not dealt with the consequences of radical uncertainty and subjective expectations:

“Kirzner initially saw his project as improving neoclassical economics and providing a ‘story’ as to how markets adjust, whereas the kaleidic Lachmann-inspired wing (including Shackle and Loasby) seems to have been reaching out to Post keynesians such as Davidson. Indeed, in their debate with Davidson [1989, 1993] both Prychitko (1993) and Torr (1993) acknowledged the tension between the kaleidic wing of Lachmann, Shackle and Boulding, with their stress on divergent and disequilibrating expectations, and the more dominant, market-as-an-equilibrating-process axis of Mises, Hayek and Kirzner” (Dunn 2008: 136).

Subjective expectations and the instability of investment are factors that destroy the myth of equilibrating markets that return to what neoclassicals call full employment equilibrium. These factors also destroy the basis of the neoclassical view from loanable funds theory that, if there is an increase in saving, then the rate of interest would fall, which will stimulate investment in production by an equal amount. This idea that an increase in saving due to a fall in consumption would not decrease aggregate demand because there is a corresponding increase in investment in capital goods to compensate for the fall in consumption is an assumption underlying Say’s law, from which it is concluded that aggregate demand will remain the same and only its composition will alter. But subjective expectations in the investment decision destroy any such automatic process to create the necessary investment.

It seems to me that Austrian business cycle theory (ABCT) as (for example) described in Garrison (1997), which also relies on loanable funds theory, makes a similar mistake: ABCT assumes a mythical “natural rate of interest” that occurs when increased savings in loanable funds (and not fiduciary media or fiat money created by the central bank) lowers the interest rate and that money is borrowed by business in a “sustainable” growth path. But what guarantee is there that business will even use those increased savings in capital goods investment under subjective expectations? If those increased savings are not borrowed for investment, you have a failure of aggregate demand. ABCT also makes the mistake of assuming an economy running at full capacity and full employment (a false assumption clearly in Garrison 1997), when in reality there are many periods when capitalist economies have very significant idle resources.

To return to the other Austrians: as for the moderate subjectivists like Kirzner or even O’Driscoll and Rizzo, I think Paul Davidson has already dealt with them:

I have always enjoyed Gerald P. O’Driscoll and Mario J. Rizzo's The Economics of Time and Ignorance (1st edn, Oxford, UK, 1985), though I don’t agree with its conclusions. Furthermore, I have always said the ThinkMarkets blog is well worth reading.

In particular, O’Driscoll and Rizzo made some favourable comments about Post Keynesian economics:

“[i]t is evident that there is much more common ground between post-Keynesian subjectivism and Austrian subjectivism …. the possibilities for mutually advantageous interchange seem significant” (The Economics of Time and Ignorance, Oxford, UK, 1985, p. 9).

That is why they stand out in my mind, as opposed to the frankly crude, ignorant and often idiotic line up of other Austrians and their supporters on the internet.

6 comments:

Nassim Nicholas Taleb and Benoit Mandelbrot (RIP) have already read, combined, and developed extensively ideas of subjectivism and uncertainty.

Of course, they came up with their core insights independently, but their usage of Post-Keynesian and Austrian subjectivism was done later to build up further on what they already believed, and what they refined further.

Of course, neither are economists, but rather specialists on mathematical philosophy, who obtain their insights from observing and trading in financial markets.

Best of all, unlike economists, they are not second hand dealers in ideas, but people who put their money where their mouth is, and test their theories by trading in markets. It's why they are right, and economists (who never have to get back their money on their ideas) are so often wrong and forced to go back to the drawing board more often.

“Keynes’s intractable uncertainty is a deeper matter, and Taleb’s swans seem to float on the surface of it. Keynes used this concept to describe a world where the future outcomes of today’s economic decisions are largely influenced by agents’ current behavior and beliefs. … Paul Davidson has reformulated Keynes’s assumption of uncertainty in terms of the nonergodic hypothesis. Uncertainty cannot be permanently reduced, but the consequences of uncertainty can be controlled by devising institutional arrangements … and using the properties of a sovereign monetary system. System robustness increases when public policies address a system’s failures through the provision of demand and liquidity” (Terzi 2010: 564).

And from the policy perspective, Taleb’s Darwinian approach is self-defeating in a non-ergodic system with ontological uncertainty.

“survival of the fittest is a self-defeating approach under ontological uncertainty: in a nonergodic world, a strategy that succeeds under given conditions may fail under different conditions. To pursue the analogy, even Taleb’s black swan argument may face its own “black swan”!" (pp. 564-565).

So I would have to say that the Post Keynesian concept of uncertainty is better than Taleb’s.

The claims of "Darwinism" are strange, given that there is not a single mention of evolution, natural selection, Darwinism,.etc in The Black Swan. None that I can recall, in any case.*

Taleb was not out for policy with his book.

He wanted ordinary people to understand the nature of uncertainty in life. In many ways, the Black Swan seemed to aim towards getting people to understand the problem of unexpected events on an emotional level.

A significant part of the book, for example, deals with how Iranians, Lebanese,.etc never understood that their countries will never go back to normal in their lifetime. The Iranians who fled Iran thought the Islamic Revolution was a historical accident soon to be reversed. They are still waiting to go back! So do Lebanese Christians in US, who think Hezbollah is a temporary problem. They believe life is a straight line, and that Hezbollah and the Shah are just "standard deviations" from the norm. They suffer from confirmation bias, (a psychological problem also faced most by policymakers).

*(The most that he ever said was that the problems of uncertainty are such that a private business can only lose its money and resources from failed predictions, while governments can ruin lives of millions from failed predictions - hence his RELUCTANT acceptance of free markets. Reluctant, because he explicitly said he did not like an unequal, unflattened world.)

Mises' praxeology is a very disputed thing. Referring to it with a huge blanket statement doesn't do much to show how you've actually dealt with the modern austrian's work in the Mises-Hayek-Kirzner tradition, versus the Mises-Rothbard tradition.